1. Field of the Invention
The present invention relates to a diagram recognizing system and, more particularly, to a diagram recognizing system so adapted as to recognize a diagram to be employed for describing a specification for data processing, such as flowcharts, data flow diagrams, and the like, of documents for developing and maintaining a data processing system, to convert the recognized diagram into logical data indicative of its logical meaning, and to generate the logical data.
2. Description of the Related Art
Recently, there have been proposed and employed techniques for analyzing and designing a system, having both accuracy in the specification for data processing and ease in understanding it, by representing a procedure of the data processing for a data processing system or the like.
For instance, such techniques may include a structured analysis technique proposed by T. DeMarco (DeMarco, T.; Structured Analysis And System Specification; Prentice-Hall, 1978) and a technique for information engineering, systematized by J. Martin (Martin, J.; Information Engineering, Book I: Introduction, Prentice-Hall, 1989).
As a specific example of these techniques, there is commercially employed a reverse engineering system for forming an entity relationship diagram from definition data of DB2, IDMS, VSAM, and IMS, which are IBM's database and files, as a tool for forming a logical structure of data from the database definition data of text file data such as a source program of a developed information system, database definition data, job control statement, linkage parameter, input-output map, and the like, as indicated by Data Analyst of Buchman, Inc. (Sato, M.; CASE Tool; Explanation of Its Functions and Know How of Its Application, page 219, Nov. 1, 1989).
On the other hand, as CASE (Computer Aided Software Engineering) tools for aiding operations for forming a source program on the basis of these techniques, there have been commercialized Excelerator (Index Technology, Inc.) and IEW (Information Engineering Workbench: KnowledgeWare, Inc.), which are employed mainly in the U.S. and Europe (Nakamura, M.: Evolving CASE; Exploding "Walls" Among Steps & Providing Smooth Development Environments: Nikkei Computer; pages 78-101, Nov. 5, 1990).
It can be noted, however, that the CASE tools, which set fourth the formation of a diagram as a premise, are thought to spread even in the U.S. at a rate as high as 10%, so that the situation is not yet ripe in which system analysts and system engineers can always utilize the CASE tools. Hence, system analysts and system engineers are usually employing techniques for manually drawing diagrams with rulers, templates and the like and allowing operators to enter the diagrams into the CASE tools or for forming diagrams by making use of drawing software, which is far less expensive than the CASE tools, and entering the formed diagrams into the CASE tools.
The diagrams formed manually or through the drawing software in the manner as described hereinabove, however, are independent from the CASE tools, so that the delivery to downstream steps, such as the verification of matching with the specification as the CASE tool, the editing to be done with the logical meaning of the diagrams taken into account, and the automated formation of engineering data or a source program, should be conducted by manual operations. Hence, these techniques present the problems that the verification of accuracy of conversion operations, compliance of the specification with the program, maintenance of the diagrams, and the like are rendered very difficult.
To this end, demands have been made to develop and realize a system that can automatically recognize a diagram formed manually or through drawing software and deliver the diagram to the CASE tool without any manual assistance.
It can be noted herein that, as a similar technique, for instance, Hitachi, Ltd. has commercialized an intelligent system for recognizing account books and vouchers (BELIEVE) (Tsuchiya, M.; Jimu to Keiei: An Intelligent System for Recognizing Account Books & Vouchers As An Instant Power Potential; pages 8-10, September, 1990). This system, enters accounting vouchers and slips as data of an image, allows a recognition of a voucher style and a recognition of fields, and automatically forms programs for implementing operations for issuing the vouchers and printing the books.
Further, Japanese Patent Publication Laid-open (kokai) No. 71,366/1990 discloses a system for forming an E-R model, which is so adapted as to enter an entity relationship diagram (an E-R model diagram) for forming a model of data within an information system, as data of an image, and to allow a graphic recognition to thereby form the E-R model in an automatic way.
In addition, as indicated by M. Hirata (An Input System for Automatically Entering Drawings of Logical Circuits: Demonstrating Its Effect by Restricted Uses; Nikkei Computer Graphics; page 18, February, 1988), a system for automatically recognizing a drawing of a logical circuit, developed by Matsushita Electric Industries, Co., Ltd., is so adapted as to read the drawing of the logical circuit of hardware as data of an image, to recognize symbols, characters, and relationships of connection between the symbols, and to store them in a database.
The system for automatically recognizing the drawing of the logical circuit, however, is so adapted as to enter the drawing of the logical circuit of the hardware, so that it cannot be applied to the recognition of a diagram describing a data system. The diagram describing the data system offers the characteristics that it is important to distinguish the directivity of the relationship of connection between the symbols, that the number of connecting lines to be connectible to each of the symbols is optional, that there is regularity among the connectible symbols, that the shape and the meaning of each of the symbols can be modified or added for each user, and the like. Hence, the problem resides in the fact that the automated system cannot be applied to the recognition of diagrams such as data flow diagrams, entity relationship diagrams, flowcharts, and the like.
Further, the intelligent system for recognizing the account books and vouchers, as described hereinabove, is so designed as to recognize formats, such as account books and vouchers composed of spreadsheets which are delimited and surrounded by straight lines only, to detect positions of the characters within the format, and to recognize the data. This system, however, cannot recognize diagram data unless the positions of symbols, connecting lines or a sequence of characters have been defined in advance.
Furthermore, the system for forming the E-R model as described hereinabove is designed exclusively for forming the entity relationship diagram in which the number of symbols to be employed is limited to several kinds; hence, it has the problem that, although it can be applied only to the recognition of the shape and the meaning of a predetermined diagram, it cannot be applied to the recognition of a diagram that should be defined by each user in a manner as have conventionally been conducted.